How does Ergatta calculate SPM?
We measure the amount of time (gap) between the start of the drive in stroke 1 and the start of the drive in stroke 2. We then take a rolling average of those gaps, and extrapolate that over 60 seconds, to calculate the SPM.
- Gap between stroke 1 and stroke 2 = 2.5 seconds
- Gap between stroke 2 and stroke 3 = 3.5 seconds
- Average gap = 3 seconds
- Extrapolated SPM = 20 (60 divided by average gap in seconds)
As you can see, we now use a rolling average over two gaps. Previously, we used a rolling average over 4 gaps.
We changed our calculation due to: feedback from users that our previous method was too laggy and this calculation is more indicative of your actual performance. Our new calculation of SPM is more sensitive to small changes.